Method and apparatus for vulcanizing hollow articles



Feb. 23 ,1926. R 16,271

A. E. FALOR METHOD AND APPARATUS FOR VULCANIZ ING HOLLOW ARTICLES Original Filed Feb. 13, 1922 4 c/firamZ. Wald?" 47 WW, (2 44%? M fli iya Reissued Feb; 23,. 1926.

UNITED STATES."

-"Re. lF-,Z7l PATENT OFFICE.

ABRAM E. FALOR, OF AKRON, OHIO, A SSIGNOR TO THE B. GOODRICH COMPANY,

OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD AND APPARATUS FOR VULCANIZING HOLLOW- ARTICLES.

Original No. 1,481,892, dated January 29, 1924, Serial No. 536,172, filed February 13, 1922. Application for reissue filedJanuary 11, 1926. Serial No. 80,681.

To all whom it may concern:

Be it known that I, ABRAM E. FALOR, a citizen of the United States, residin at Akron, in the county of Summit and tate of Ohio, have invented a certain new and.

useful Method and Apparatus for Vulcanizing Hollow Articles, of which the following is a specification. This invention relates to methods and apparatus for vulcanizing hollow articles. such as annular rubber tubes. In the case of inner tubes for pneumatic tires, for example, when vulcanized in annular form, the raw tube is placed in a two-part mold, against the walls of which it is expanded by internal fluid pressure. Such internal pressure has been provided in various ways, but certain disadvantages have attended the several methods.

vided by sealingwater in the tube before enclosing the latter in the mold, to be converted into steam by the application of heat through the mold walls, excessive time is re-. quired for the pressure-to build-up within the tube. If compressed air is injected substantially all of the vulcanizing heat must reach; the tube through the" walls of the mold, and this requires considerable time. If steam is injected, as has heretofore been proposed, through the valve-stem 'of the tube, the latter being mounted in its final position in the wall of the tube, the tube is quickly heated from within by "the injected steam, but the vulcanization of the tube'is not uniform because the incoming jet of steam impinges on the wall of the tube opposite the valve stem and over-cures the stock at that locality and the pressure of the valvestem head or flange against the inner face of'the tube causes a displacement of rubber and consequent thinning of the tube wall during vulcanization, with the re sult that a less rugged and permanently airtight sealing of the valve stem to the tube wal1 is obtained than when the valvestemhead is drawn into sealing engagement-with the inner face of the tube wall after the latter has been vulcanized, as in the practice of curing tubes on straight mandrelsand thereafter mounting the valve stems therein.

My chief objects are to provide a methodv If the internal pressure is proinner periphery,

such as steam without local overcuring or scorching of the stock, and to provide apmethod. a

A further object is to'provid'e procedure and apparatus whereby a hollow article such as an endless inner tube,-having a single ap ertur'e for an insert such as a valve stem, may be vulcanized under internal fluid pressure with the insert so supported in its interior paratus suitable for carrying out saidas not to contact, deface ordamage the wall of the article during vulcanization, and the insert then mounted-in the wall of the article notwithstanding its being formed withv a head such as would make it diflicult or undesirable to force the head through the insert aperture after vulcanization. I

'Of the accompanying drawings: Y

Fig. 1 is a side elevation, partly in section of apparatus embodying and adapted to carry out my invention, said apparatus comprising a multiple hot-plate vulcanizing press and a plurality of tube molds therein.

Fig. 2 is a plan view, with parts broken away and in section, of a'lower mold section with an inner tube there 1n..

'-Fig.'3 is a perspective viewof a part of an inner tube, with parts broken away and in section, showing the tubu'larvalve stem or casing in its final relation to the body of the tube. I v

Referring to the drawings, 10 is the lower section of a two-part inner-tube mold formed 1 with a projection 11 extending from its formed with a'radial groove 12 (Fig. 2) across its upper surface, said groove being adapted to receive a steam-inlet pipe 13 and being locally enlarged to accommodate said projection being a collar or lug 14 secured to said pipe andv I a stud 15 projecting from said collar, said collar and stud thus being adapted to prevent said pipe from sliding or turning in said groove.

The inlet pipe 13 extends. through the valve stem hole in the wall of an inner tube 16 lying within the mold-section 10 and has an L-bent end portion 17 within said tube, said end portion substantially coinciding with the longitudinal axis of the tube. Said end portion 17 is provided at its extremity with an internally threaded enlargement 18,

into which ,is screwed an inner-tube inflat ing-valve stem or casing 19, which is thus 9 er end'detachably joined by a coupling 26 held in a t-angential or coaxial position with respect to the tube. v

The upper mold section, 20 (Fig. 1), is formed with a projection 21 extending from its inner periphery and so formed asto fit the projection 11 of; the lower. mold section and the pipe 13 and collar 14 mounted therein. 22 (Fig. 1) indicates the continuation of the registering flange of the lower mold 0 section across theprojection 11, theprojection 21 of the upper mold section being formed with a complementary groove'to receive said flange. i

At a point preferably diametrically op 3. positethe projection 11, the lower mold section is traversed by a groove 23, across its lower, face, accommodating a fluid-pres- I sure pipe .24 detachably connected with the inlet pipe 13 by a coupling-25, and at its oth- (Fig. 21), with a flexible fluid-conduit 27 branching from a steam supply-line 28/ I donotwholly limit my claims, however, to this specific means for conducting steam or other pressure fluid to the inlet pipe-13, or

, pipe.

to a direct pipe connection with said inlet The several assembled mold sections 10, 20, may be used indifferent types of presses.

They are here shown mounted ina press of the hot-plate jype comprising a fixed top plate 29 under the upper cross-head or platen of the press, a bottom plate 30 mounted on the head 31 of a hydraulic ram 32, said head constituting the movableplaten of the press,

and intervening plates-33,- 33 slidably mounted between the tie-rods 34, 34 of the press.-

- 35 is a steam supply-line from which a branch pipe 36 leads to the fixed upper plate, and

for heatmg the respective plates. The usual shown) may'be provided. 38, 38 are horizontal bars having their'ends mounted in the vertical tie-rods 34 and adapted to-s'uppor't the intermediate plates 33 in spaced relation when the ram 32 is lowered to permit the in sertion or removal of the molds.

In' practicing my method with the improvedapparatus here shown, the'inner tube 16 is formed in any known or ap roved man: ner and assembled with the tu ular valvestem or casing 19, inside th'ereof, and the inlet pipe13, the latter; extending through the valve-stem hole of the-tube. This may k be doneby first forming the rubber tube straight, inserting in the valve-stem hole thereof the inlet pipe.- 13, placing the valve-- be joined therewith. 'tion 20 is then placed in position on the flexible pipes 37, 37 lead to the other plates,

thereof.

section '10 and the inlet pipe 13 is mounted in the groove 12 of the mold-sections projection 11, the stud, 15 on the collar 14'as- .suring that the valve-stem 19 will lie in a from the last operation, or if previously disconnected from said inlet pipe 13 it may now The upper mold'seclower mold section, the mold, or a plurality of molds, inserted'in the press, the pipe or pipes 24 connected with the pipe or pipes 27, and tl1e -press closed. -Hot pressure fluid,

-- preferably steam, is then injected into the interior of the tube 16 from the supply line 28, expanding the tube against the wallsof the mold. The tube is thus vulcanized by the applicatibn of heat directly to its inner surface as well as from'the adjacent hotplates, through the mold sections, to its outer surface. Ido not wholly limit myclaims, however, to conducting pressure fluid into the tube top'rovide expanding fluid pressure therein during cure. t

Dueto the tangential position of the valve v stem 19, through which the heating fluid enters the tube, direct impingement of a jet against the wall of the tube, and consequent local over-curing of the latter, is avoided, I

and as the jet is tangential it sets up a rapid longitudinal circulation of fluid through the tube, so that parts 'of the latter diametrically opposite the point of injection are "heated substantially as quickly as those at the point of injection. A uniform cure is thus obtained, while time is saved by the directapplication of heat to the interior of the tube.

After the vulcanization is complete, the coupling 26 is disconnected, the mold removed, the press opened, and the valve-stem 19- is drawn through the .wa'll of the tube to its final radial position by means of the inletpipe 13. The latter is then disconnected from the valve stem, and the bead-spreader lug 39 and retaining nut 40 therefor are mounted onsaid stem in their usual relation, as shown in Fig. 3.

- An effective sealing of the valve-stem head against the inner face of the tube about the lbs valve-stem aperture is'obtained without the necessity of forcing the valve-stem {head through the aperture. The inner surface of thetube .which'seals against the valve-stem head is vulcanized. in asmooth condition, out of contact with the said head, so that a defective valve-stem may be readily replaced by a new one with an effective sealing The internal fluid pressure during the cure causes the adjacent portion of the tube wall including the valve-stem patch 16 to press'and seal against the inlet'pipe 13 to prevent escape of the pressure fluid through the valve-stem aperture of the tube.

My invention is not limited to the specific construction shown or the exact course of procedure described, except as defined in the appended claims. It may also be used for vulcanizing other annular hollow rubber articles, such as bicycle tires. 4

I claim: j

l. The method of vulc'anizing an annular rubber tube which comprises enclosing said tube in a mold and pressing it against the walls thereof by a hot pressure fluid injected tangentially at apoint remote from the wall of the tube, said fluid being injected in one tangential direction only, so as to cause a complete circumferential circulation of said fluid in said tube. 2. The method of vulcanizing annular rubber tubes which comprises injecting steam into the tube tangentially thereof at the cen tral region of the cross-section thereof, and in one tangential direction only. I

3. The method of vulcanizing an annular inflatable article such as a pneumatic tire or inner tube, said method comprising enclosing the inflating-valve casing in the tube, at

' taching a supply-pipe thereto and positioning the valve-casing tangentially, enclosing the tube in a. vulcanizing 'mold, injecting steam tangentially through said valve casing until the tube is vulcanized, an'd finally fixing the valve casing radially in the tube ,wa-ll.

4. Tube-vulcanizing apparatus comprising an annular'tube-mold, and means for injecting a heating fluid tangentially thereinto in one tangential direction only at a point remote from the wall of the tube.

' 5. Tube vulcanizing apparatus comprising an annular tube-mold, and a fluid .inletconduit having a portion extending substantially radially through the inner peripheral wall ofthe mold, and an inner terminal porvtion directed tangentially of the mold and in one tangential direction only and located in the central region of the cross-section of f the mold.

. 6. In t'ube-vtilcanizirig apparatus the-combination of an annular-t-ube-mold', and an angulary conduit having a portion passing through" the inner peripheral wall of the mold, and a tangential portion within the the article. I 7

9. The method of making a hollow article mold, threaded to receive the inlet end of an inflating-valve casing. v

7. In tube-vulcanlzing apparatus-,'the combination of a lower annular mold member traversed by a substantially radial groove, an upper annular mold section formed with a g-rooveregistrable with that of the lower mold section, and an angular pipe having a substantially radial portion occupying said grooves and an inner, tangential ,'terminal portion threaded toreceive the inlet end of the inflating-valve casing.

8. The method of makinga hollow article having an insert extending through the wall thereof which comprises placing the insert within the interior ot'the article, vulcanizing the article with the insert-therein, and thereafter mounting the insert in the wall of having an insert extending through the wall thereof which comprises forming the article with the insert within the interior thereof and with an insert-receiving aperture in the wall thereof, supporting the insert within but out of contact with the wall ofthe arti cle by means extending through the said aperturewhile vulcanizing the article, and thereaftermounting the insert in the said aperture. v

10 The method ofmaking a'hollow' arti cle having an insert extendingthrough the wall thereof which comprises forming the article with an insert-receiving aperture in the wall thereof, supporting a headed insert with its head within the article but out of contact with the wall thereof,'by means ex tending through the ,said aperture, whilevulcanizing the article, and thereafter drawing the head of the insert against the inner surface of the article, about the aperture, to seal it thereagainst. V

l1.v Vulcanizing apparatus comprising a mold for a hollow article and amember pro-Y jecting from the mold into the cavitythereof and having its portion within the said cavity formed to receive-and support an inthe Wall of the art'icle. Y

In witness whereof I have hereunto set 'sert suitable to be mounted in an aperture in my hand thisfitli day of January, 1926.. v

:ABRAM E. FALOR. 

